Method for the surface modification of formed bodies and formed bodies produced thereby

Abstract

Fabrication of the surface-grafted microporous membranes by coating the membrane with an N-halogenated compound, followed by grafting with an unsaturated monomer and sodium dithionite in a primarily aqueous solution that may contain an organic halogen compound selected from carbon tetrachloride and trichloroacetic acid. The coating may be formed in situ and may be cross-linked.

We claim: 
     
       1. A method of grafting polymerized components onto the surface of a polymeric microporous support membrane comprising the following steps: (a) providing a polymeric microporous support membrane;   (b) forming a coated support membrane by coating said support membrane with a coating comprising an N-halogenated compound selected from an N-halogenated polymer and an N-halogenated polymeric precursor; and   (c) grafting said coating to said coated support membrane by contacting the same with an ethylenically unsaturated monomer and sodium dithionite in a primarily aqueous solution.   
     
     
       2. A method of grafting polymerized components onto the surface of a polymeric microporous support membrane comprising the following steps: (a) providing a polymeric microporous support membrane;   (b) forming a coated support membrane by coating said support membrane with a coating comprising an N-containing compound selected from an N-containing polymer and an N-containing polymeric precursor wherein said N has bonded thereto at least one hydrogen atom substitutable by halogen; and   (c) grafting said coating to said coated support membrane by contacting the same with an ethylenically unsaturated monomer and sodium dithionite in a primarily aqueous solution that contains an organic halogen compound selected from carbon tetrachloride and trichloroacetic acid.   
     
     
       3. The method of claim 1 or 2 wherein said ethyenically unsaturated monomer is selected from the group consisting of Methylmethacrylate,   Ethylmethacrylate,   Hydroxyethylmethacrylate,   Methacrylamidoglycolate methylether,   Glycerol methacrylate,   Glycidyl methacrylate,   Glycerol acrylate,   Glycidyl acrylate,   Diethylaminoethylmethacrylate,   Dimethylaminoethylmethacrylate,   Sulfopropylmethacrylate,   N-morpholinopropylmethacrylamide,   N-morpholinoethylmethacrylate,   Dimethylaminopropylmethacrylamide,   Vinyl pyrrolidone,   N-hydroexyethylmethacrylamide,   N-acrylamidoglycolic acid,   N-[tris-(hydroxymethyl)]-methylmethacrylamide,   N-[tris-(hydroxymethyl)]-methylacrylamide,   Methacrylamide,   2-acrylamino-2-methyl-propane sulfonic acid,   Triethylammonium-2-hydroxypropylmethacrylate chloride,   Methacrylamidopropyltrimethylammonium chloride,   Diethylaminoethylmethcrylate,   Diethylene glycol methacrylate,   Methacrylate,   Ethylacrylate,   Hydroxypropylmethacrylate,   Hydroxyethylacrylate,   Hydroxypropylacrylate,   Acrylamide,   Vinyl acetate,   Octaethylene glycol methacrylate,   Vinyl imidazol,   Methylvinyl acetamide,   4-vinyl pyridine,   Acrolein and   Methacrolein.   
     
     
       4. The method of claim 1 or 2 wherein said ethylenically unsaturated monomer is selected from the group consisting of: Pentaerythrite dimethacrylate,   Glycerol dimethacrylate,   Glycerol diacrylate,   Glycerol trimethacrylate,   Glycerol triacrylate,   Tetraethylene glycol dimethacrylate,   Tetraethylene glycol diacrylate,   Trimethylol propane triacrylate,   Trimethylol propane trimethacrylate and   Methylene bisacrylamide.   
     
     
       5. The method of claim 1 or 2 wherein said coating on said coated support membrane is formed in situ. 
     
     
       6. The method of claim 1 or 2 wherein said coating on said coated support membrane is cross-linked. 
     
     
       7. The method of claim 1 or 2 wherein said coating on said coated support membrane is selected from polyamides, polysulfonamides, polyurethanes, polyureas, and monomeric precursors of the same. 
     
     
       8. The method of claim 7 wherein said coating is a polyamide selected from an N-hydroxymethylated and an N-methoxymethylated polyamide. 
     
     
       9. The method of claim 7 wherein said coating is a polyurea formed by a reaction between a diamine and a diisocyanate. 
     
     
       10. The method of claim 1 or 2 wherein said polymeric microporous support membrane is selected from the group consisting of cellulose, cellulose acetate, cellulose hydrate, cellulose nitrate, polysulfones, polyether sulfones, polyolefins, halogenated polyolefins, polyesters and homo- or copolymers of acrylonitrile. 
     
     
       11. The product of the process of claim 1 or 2. 
     
     
       12. The product of claim 11 wherein said ethylenically unsaturated monomer is glycidyl methacrylate. 
     
     
       13. The product of claim 12 wherein, following step (c), the resulting membrane product is post-treated by a method selected from: (a) sulfonation of epoxide groups of said glycidyl methacrylate by treatment with sulfite ions;   (b) quaternization of epoxide groups of said glycidyl methacrylate by treatment with a tertiary amine; and   (c) formation of a tertiary amino group by conversion of epoxide groups of said glycidyl methacrylate with a secondary amine.